History YMMV / CrusaderKings

** To counter the accusation that Germanic pagans [[note]]the Norse religion; the religion was renamed as Norse as a culture is also present in-game [[/note]] got all the attention while other pagans got shafted, ''Holy Fury'' added Eldership succession to African and Romuvan followers[[note]]Before this, pagans pretty much can only use gavelkind-style successions, which splits the realm easily. Eldership ensures that one heir inherits the realm.[[/note]], and a warrior lodge society to all pagan religions (except Aztecs). Also, ''Holy'' revamped the pagan reformation system, allowing the reformer to customise the reformed pagan faith.

** To counter the accusation that Germanic pagans [[note]]the Norse religion; the religion was renamed as Norse as a culture is also present in-game [[/note]] got all the attention while other pagans got shafted, ''Holy Fury'' added Eldership succession to African and Romuvan followers[[note]]Before this, pagans pretty much can only use gavelkind-style successions, which splits the realm easily. Eldership ensures that one heir inherits the realm.[[/note]], and a warrior lodge society to all pagan religions (except Aztecs).

** Hellenism is also a major source of feuding, including arguments over whether it was still practiced at all combining with the desire of a certain portion of the playerbase to play Hellenic anyway, and a VocalMinority repeatedly demanding that the developers provide support for it (and triggering a CreatorBacklash over the whole issue). When Paradox decided to add the option to revive Hellenism in "Holy Fury", they added a game rule to allow players to disable the events that can revive the religion (and made them difficult enough that the AI has little chance in succeeding in them) because of the strife the issue has brought in the fandom.
** ''Way of Life'' introduced focuses, some of which (especially seduction for the adultery and business for the "free money" event) are viewed by a very vocal group of players as gamebreakers.

*** Your basic Muslim has Iqta government instead of normal Feudal, which allows nobles to freely hold mosques instead of only castles, meaning higher income from both the temple(s) and the fact that Iqta tax law defaults to 10% on both castles and mosques, making them usually richer than any Christian nation. [[note]] While the Conclave [=DLC=] changed it such that Christian nobles will pay some tax by default, ''Catholic'' clergy still retain their unique mechanic of ''only'' paying taxes to the Pope and withholding their levies, if they like the Pope more than their secular liege. Needless to say, a pious Pope would be a significant drain on both income and levies for Catholic realms.[[/note]] Muslims are restricted to open succession unless the council is fully empowered, meaning that the vassals cannot form factions to change the succession law (a source of civil wars) [[note]]In addition, at early start dates, many Christian realms use gavelkind succession, which can easily split apart large realms when succession takes place[[/note]]. In early start dates, they also begin with two strong realms, the Umayyads in the west and the Abbasids in the east, whereas Catholic Europe is very divided and it's common to see Charlemagne die before he can form the Holy Roman Empire to rival the Umayyads, and only the Byzantine Empire poses a significant threat to the Abbasids. In addition, the game doesn't model the things that historically made the Spanish Visigoths not worth the Moors' trouble to conquer (i.e. that they were poor and good guerrilla fighters). [[note]]If anything, game mechanics make Asturias an even ''more'' attractive goal to conquer. First of all, Asturias lies in the same ''de jure'' empire (Hispania) as the territory the Umayyads control, which meant that the Muslims could muster more levies from the territory once it is conquered, as compared to other regions which lie outside Hispania. Next, a special creation condition for the Empire of Hispania is that its constituent kingdoms are not held by infidels. Thus, for the Umayyads to form Hispania, they ''have'' to fight the Spanish Visigoths until they ''at least'' lose the Asturian crown.[[/note]]

** [[https://forum.paradoxplaza.com/forum/index.php?threads/ck2-dev-diary-41-secret-religious-cults.999496/ This dev diary]] for ''Monks and Mystics'' included a shot of a new trait, "Secretly Sunni" (for somebody who outwardly followed a different faith but secretly was a Sunni Muslim). The AlliterativeName quickly got the players coming up with names for corresponding traits such as "Reclusively Romuvan", "Surreptitious Suomenusko", and "Covertly Cathar".
** China confirmed! [[note]]"Expand the game to China!" has been a base-breaking cry ever since the earliest map expansions. Every expansion that's ever announced has someone theorizing that China's going to be a part of it. Finally confirmed for realsies with ''Jade Dragon''.[[/note]]

** As a Catholic, having a vassal Pope (which can be achieved by making an Antipope and pushing his claim on Rome, making him the official Pope). Putting aside that you need to be an Emperor to have one in the first place, once you have one you get free claims on any Catholic duchy or county in the game and the power to excommunicate any catholic character who annoys you, letting you imprison them penalty-free and making it nigh impossible for them to form factions. This doesn't so much break normal mechanics for vassal management and expansion as snap them neatly in half. ([[ObviousRulePatch This is set to be patched]] in ''Holy Fury''.)

*** Your basic Muslim has Iqta government instead of normal Feudal, which allows nobles to freely hold mosques instead of only castles, meaning higher income from both the temple(s) and the fact that Iqta tax law defaults to 10% on both castles and mosques, making them usually richer than any Christian nation. [[note]] While the Conclave [=DLC=] changed it such that Christian nobles will pay some tax by default, ''Catholic'' clergy still retain their unique mechanic of ''only'' paying taxes to the Pope and withholding their levies, if they like the Pope more than their secular liege[[/note]] Muslims are restricted to open succession unless the council is fully empowered, meaning that the vassals cannot form factions to change the succession law (a source of civil wars) [[note]]In addition, at early start dates, many Christian realms use gavelkind succession, which can easily split apart large realms when succession takes place[[/note]]. In early start dates, they also begin with two strong empires, the Umayyads in the west and the Abbasids in the east, whereas Catholic Europe is very divided and it's common to see Charlemagne die before he can form the Holy Roman Empire to rival the Umayyads, and only the Byzantine Empire poses a significant threat to the Abbasids. In addition, the game doesn't model the things that historically made the Spanish Visigoths not worth the Moors' trouble to conquer (i.e. that they were poor and good guerrilla fighters). [[note]]If anything, game mechanics make Asturias an even ''more'' attractive goal to conquer. First of all, Asturias lies in the same ''de jure'' empire (Hispania) as the territory the Umayyads control, which meant that the Muslims could muster more levies from the territory as compared to other regions which lie outside Hispania. Next, a special creation condition for the Empire of Hispania is that its constituent kingdoms are not held by infidels. Thus, for the Umayyads to form Hispania, they ''have'' to fight the Spanish Visigoths until they drop the Asturian crown.[[/note]]

*** Italian and Scottish pike retinues also score very high as retinues go. See the above section on Defense retinues? Well, Italian or Scottish pikes are basically those, but with some decent punching power on top of it. Because they count as Heavy Infantry they're also very good at StormingTheCastle (unlike Cavalry and Light Infantry retinues who dominate battlefields but are terrible at sieges).
** As a Catholic, having a vassal Pope (which can be achieved by making an Antipope and pushing his claim on Rome, making him the official Pope). Putting aside that you need to be an Emperor to have one in the first place, once you have one you get free claims on any catholic duchy or county in the game and the power to excommunicate any catholic character who annoys you, letting you imprison them penalty-free and making it nigh impossible for them to form factions. This doesn't so much break normal mechanics for vassal management and expansion as snap them neatly in half. ([[ObviousRulePatch This is set to be patched]] in ''Holy Fury''.)

* dBugs:

*** The horse character spawns with a special Horse trait that makes them infertile, normally preventing this. However, a [[dBugs workaround]] exists for religions that can nominate heirs to bishoprics (i.e. just Catholics in an unmodded game). Nominating the horse as the heir to a county bishopric will cause a bunch of horse courtiers to spawn when the horse inherits the title. These newly generated horse characters ''do not'' have the Horse trait, and can be [[BestialityIsDepraved married/seduced and used to conceive]] [[HalfHumanHybrid horse children]]. This allows for such strangeness as a [[NinjaPirateZombieRobot female horse Viking]] [[https://imgur.com/a/K1utf restoring the Roman Empire]]. For religions without priest investiture, you can educate a child with the horse and Heritage focus until he converts culture, then land the child to cause horse courtiers to appear.

*** Your basic Muslim has Iqta government instead of normal Feudal, which allows nobles to freely hold mosques instead of only castles, meaning higher income from both the temple(s) and the fact that Iqta tax law defaults to 10% on both castles and mosques, making them usually richer than any Christian nation. Muslims are restricted to open succession unless the council is fully empowered, meaning that the vassals cannot form factions to change the succession law (a source of civil wars). In early start dates they also begin with two strong empires, the Umayyads in the west and the Abbasids in the east, whereas Catholic Europe is very divided and it's common to see Charlemagne die before he can form the Holy Roman Empire to rival the Umayyads, and only the Byzantine Empire poses a significant threat to the Abbasids. In addition, the game doesn't model the things that historically made the Spanish Visigoths not worth the Moors' trouble to conquer (i.e. that they were poor and good guerrilla fighters).

* GoodBadBugs:

*** The horse character spawns with a special Horse trait that makes them infertile, normally preventing this. However, a [[GoodBadBugs workaround]] exists for religions that can nominate heirs to bishoprics (i.e. just Catholics in an unmodded game). Nominating the horse as the heir to a county bishopric will cause a bunch of horse courtiers to spawn when the horse inherits the title. These newly generated horse characters ''do not'' have the Horse trait, and can be [[BestialityIsDepraved married/seduced and used to conceive]] [[HalfHumanHybrid horse children]]. This allows for such strangeness as a [[NinjaPirateZombieRobot female horse Viking]] [[https://imgur.com/a/K1utf restoring the Roman Empire]]. For religions without priest investiture, you can educate a child with the horse and Heritage focus until he converts culture, then land the child to cause horse courtiers to appear.

** The concept of adding new content via DLC system itself is probably ''the'' biggest issue in the grand picture of things, spreading to other Paradox games, but it started with [=CKII=]. Before the game, any sort of new content was added by overhaul patches, which meant every player had access to the exact same content and it wasn't hidden behind extra paywall. Money aside, this lead to much higher stability of games, since there was just one existing itteration and all gameplay mechanics were always in interaction, making both achieving stability and debugging easier and faster. With DLC system, all of that goes to a bin, since [=DLCs=] are disjoined from each other and their content exists in a bubble. With just few initial [=DLCs=] crunch time spiked, as there were numerous itterations of the game and combinations of DLC content to test, check and work with. It also made modding needlessly complex, as modders faced the exact same issue, while not being a game studio with money and manpower for longer crunch time. All in all, this drastically increased the time for delivering each new change into Paradox games.

** Sunset Invasion has plenty of this, courtesy of the invading Aztecs. Gigantic armies arriving from across the Atlantic, horrible diseases Old World people have little resistance to, mass human sacrifice of captives, and more horrors are all on the table.

* WhatDoYouMeanItsNotPolitical: [[OpenMouthInsertFoot Paradox unintentionally got into a bit of hot water]] with a March 2018 promotion where ''[=CK2=]'' was free to keep on Steam for a couple days. They announced this with a tweet that included the phrase "deus vult", which [[http://www.newsweek.com/paradox-interactive-875640 unfortunately for Paradox had become a slogan for various white supremacist groups in the years since the game's release]]. Cue a minor InternetBackdraft and Paradox having to explain their intent and the historical context in a response.

** Crusade for Orissa.[[note]]AI heads of religion with crusades have a list of possible kingdoms they can target, which are chosen at random. Though possibilities that are important for the faith are weighted higher (e.g. the Pope will almost always hit Spain first if it's still partially or fully under Moorish control), there's always the chance that they'll pick some wild-ass destination (especially after all the obvious ones have been taken). Like Orissa, which is on the eastern coast of India. Cue half of Europe dying of starvation as it marches for years on end all the way to India.[[/note]]

** The d'Hauteville family, the Norman rulers of southern Italy and later the kingdom of Sicily before their country was inherited by the Hohenstaufens, are a very popular choice among players, apparently. Reasons for this include a very convenient geographic position in the middle of the Mediterranean, proximity to both several small and easily conquerable nations of various religions which make it easy to expand your territory and the Papacy which makes for an interesting diplomatic partner, the absence of a Muslim superpower that tries to curb-stomp you from the get-go, and a huge number of (mostly male) family members convenient for both political marriages and diminishing the risk of interfamilial rivalry. They have basically lots of exploitable options in every aspect and don't start overpowered enough to make your achievements seem ordinary. The fact that it is reasonably easy to trump their real-life achievements certainly helps.

** ''Charlemagne'' continues the base breaking tradition. Several features in the DLC itself didn't work as planned, while the patch containing free content introduced new bugs. In addition, the fanbase is divided over the inclusion of "Zunist" pagans. It's either a fun exploration of a fascinating pre-Islamic faith in Afghanistan, or overly obscure add-on that no-one asked for, ignoring fan interest in adding content to existing religions and heresies such as Hellenism[[note]]which would have been just barely hanging on in the Mani peninsula in 769[[/note]] or Yazidism. The earlier start date has also proven controversial, with detractors saying that the feudal system as present in the game did not exist that far back.

** The Abbasids in the ''Charlemagne'' DLC's 769 start (and to a lesser degree in 867, where even the AI can easily restore their 769 borders). They start out owning a good sixth of the map as-is (Arabia, Egypt, Mesopotamia, Persia and Syria/Jerusalem) and Empires in-game tend to be much more stable than in real life, so most games started in that year end up with the 'Abbasid blob' locking down the entire Middle East for the rest of the game unless the player intentionally starts antagonising them. Unlike its historical counterparts, the Abbasids will laugh off the Seljuks and even halt the Mongols' advance into Europe. Ditto the Umayyads in 769, who start out with solid control of Andalusia, and unlike real life will invariably conquer the entirety of Spain without player intervention.
** Egypt also used to be this for a long time. Although not large, it was always a united kingdom, extremely wealthy and wedged in an easily defensible position, making it difficult to conquer it. Also, except for 769, where it is part of the Abbasid Empire, the Sultan has the [[EliteMooks Mamluks]] mercenary company as a vassal, making it easy for him to win wars that would otherwise much more difficult. The real problem was though that unlike their Real Life counterparts, Egypt would ''immediately'' turn its attention to the militarily outclassed christian Nubian Petty kingdoms and counties to the south and afterwards swallow Abyssinia even further to the south-east whole, essentially conquering the entirety of eastern Africa about 40 years into the game (and thus locking down the entire region for the rest of the game). The successful wars waged in the process would also prevent a decadence revolt from taking place. This has since been fixed by making the closest Nubian states tributaries of whoever controls Egypt at the time, but Egypt is still extremely powerful in AI, to say nothing of player hands.

*** The transition by itself means your potential (or actual empire) goes from a powerhouse to a complete wimp, on a principle that vanilla feudalism is by far the weakest of all forms of government the game has to offer, even when compared to tribal pagans. It takes another lenghty advance in administrative technology to reach anything resembling fucntional government and regain control over your own territory you had as a tribal pagan. Meanwhile, merchant republic is restricted heavily in size, so your massive conquest becomes a liability, rather than any sort of benefit. And should you be unlucky, your dynasty will be kicked out of the office of the doge right after your current ruler dies.

** Due to the way how the alliances and feudal support works in the game, it violates one of the basic "rules" of it: vassal of my vassal is not my vassal. In [=CKII=], any stage of vassalage is transferred to the top liege. So if you want to conquer any given province that's controlled by a minor, weakling lord, but who also happens to be a vassal of a vassal of a vassal to some large empire, it won't be just his liege declaring war on you. '''EVERYONE''' in said empire will go on war with you. Automatically. With no option for negotiations. This is especially annoying in terms of UsefulNotes/HolyRomanEmpire and any larger Islamic empire, because it leads to ridiculous, ahistorical situations where feuding minor lords bring entire imperial might into the fry

*** And then there is still the issue of the paywall. Pretty much entire older section of the fanbase has nothing but disdain toward the DLC model, as it charges utterly ridiculous sums to unlock the whole game. Not helping matters is how often changes brought by new pack are cosmetic or add just some minor gameplay changes or UI help (like a new button to do something automatically, rather than file-editing), with that one, single important change that's still fundamental. On the other hand, nobody is forcing anyone to get all [=DLCs=], but that means missing a lot of content. And the less is said about things that were once paid DLC and then became free content for everyone a year or two later, the better, since it's an equivalent of jet fuel for flame wars.

*** And then there is still the issue of the paywall. Pretty much entire older section of the fanbase has nothing but disdain toward the DLC model, as it charges utterly ridiculous sums to unlock the whole game. Not helping matters is how often changed brought by new pack are cosmetic or add just some minor gameplay changes or UI help (like a new button to do something automatically, rather than file-editing). On the other hand, nobody is forcing anyone to get all [=DLCs=], but that means missing a lot of content. And the less is said about things that were once paid DLC and then became free content for everyone a year or two later, the better.

** "[[AltumVidetur DEUS VULT]]." Latin for "God wills it", it was a common Western Christian motto and appears frequently in the games (up to and including having the expansion pack for the first game named for it).

* CrackIsCheaper: Though the base game's been out for a couple years by now, it's still listed on Steam at its original list price of ~$40. Since then, the series has steadily accumulated a mass of DLC expansions, none of which have yet been discounted themselves, so that to get the full functionality out of the game you'll have to spend well over $100... and that's before you get into the aesthetic unit and face packs. It's mitigated by the fact that the series goes on sale relatively frequently, but the price tag will only get worse as expansions continue to be developed.
** Another mitigation is that many popular/high quality mods make use of assets from the expansion and/or portrait [[DownloadableContent DLCs]].
** This trope ignited a firestorm when [=PI=] announced price hikes for their games (including ''Crusaders'') just before the Steam Summer Sale of 2017. It got so bad that eventually, [=CEO=] Fredrik Wester came out to confirm that the price hikes will be reverted after the Summer Sale is over.

* AntiClimax: [[https://forum.paradoxplaza.com/forum/index.php?threads/the-obligatory-ck2-strange-screenshot-thread.585791/page-977#post-20913717 The Mongol and Aztec hordes sometimes adopt local religions such as Catholicism]], which causes them to lose access to their Tribal Invasion ''casus belli'' and stops their invasion dead in its tracks.